What Is Enriched Uranium, How Much Does Iran Possess, and Is It Developing Nuclear Weapons?

The recent claim by the US President that Tehran has agreed to transfer its stockpile of enriched uranium as part of a deal to end the war has once again drawn significant attention. However, on Monday, Iran’s Deputy Foreign Minister Saeed Khatibzadeh denied this allegation in an interview with the Associated Press, stating it is impossible. As both sides continue peace talks, this issue is certain to remain a key agenda item.

But what exactly is enriched uranium and why is it important? Uranium is a naturally occurring element found on the Earth’s surface. It has two isotopes: U-238 and U-235. Natural uranium consists of about 99% U-238, which cannot initiate a chain reaction. Only about 0.7% is U-235, which fissions easily and is useful in the process of nuclear fission — the splitting of atoms to release energy.

The level of uranium enrichment determines its purpose. Low-enriched uranium contains between 3 to 5% U-235 and is commonly used as fuel in commercial nuclear power plants. It can sustain controlled chain reactions but is not suitable for weaponization. Uranium enriched to 20% or higher U-235 is considered highly enriched and is used in research reactors. To make nuclear weapons, uranium enrichment levels must reach approximately 90% U-235.

The 2015 agreement between Iran and six world powers — China, France, Germany, Russia, the United States, and the United Kingdom — limited Iran to enriching uranium only up to 3.67% and restricted its stockpiles to no more than 300 kilograms.

Currently, the talks focus on the future of Iran’s enriched uranium reserves. Senior US officials have revealed that Iran possesses nearly 440 kilograms of uranium enriched to a high level.

Iran continues to assert that its nuclear facilities are used solely for peaceful purposes. The International Atomic Energy Agency (IAEA) has reported no evidence of an active nuclear weapons program in Iran.